Do not concatenate strings to build a SQL command. It leaves you wide open to accidental or deliberate SQL Injection attack which can destroy your entire database. Use Parametrized queries instead - it will almost certainly cure your problem at the same time!
cmd = New SqlCommand("INSERT INTO Bacheli (mycolumn1, mycolumn2, myColumn3) VALUES (@T1, @T2, @T3)", com)
You will need to rename "mycolumn1" etc. to match your columns, and it would be a good idea to rename the parameters "@T1" and so on to something more sensible as well.
While we are on the subject, stop taking VS defaults for names - you may remember today what "TextBox8" holds, but when you come back to makes changes in a weeks time? Or next month? Always use sensible names instead that describe what it is used for.